Spark plug



G. J. JAcoMlNl SPARK PLUG Filed Nov. 6, 1922 Patented July 20, 1926 FATENT Q.

GABRIEL J. JAGOMINI,

OF CHICAGO, ELLINOIS.

SPARK PLUG.

Application filed November My invention relates to spark plugs, and more particularly to a self-cleaning spark plug. i

It is a purpose of my invention to provide a spark plug which will clean itself due to shocks imparted to the same, such as those due to travel of the automobile vehicle over the roadway, or due to the explosions of the mixture in the internal conibustion engine that thespark plug is mounted on, or due to a change in position of the vehicle relative to a horizontal plane.

It is more particularly a purpose of the invention to provide a spark plug having a movable electrode that is adapted to move about due to the various causes mentioned above, so as to clean itself and thus keep the spark plug clean.

It is a more specific purpose of the invention to provide a spark plug comprising a central stationary electrode and an outer movable electrode provided with means for guiding the same so as to maintain the proper spark gap between said movable and stationary electrodes. Preferably the movable electrode is made in the form of a ball or sphere and a ball race, or similar guideway is provided concentric to the central electrode for guiding the spherical member or ball in its movements.

Other objects and advantages of the invention will appear as the description of the accompanying drawings proceeds. How.- ever, I desire to have it distinctly understood that I do not intend to limit myself to the exact details shown or described, but that I intend to include as part of my invention all such obvious changes and modifications of parts as would occur to a person skilled in this art and as would fall within the scope of the claims.

In the drawings:

Fig. 1 is a side elevation partly in section of my improved sparkplug; and

Fig. 2 is a section thereof taken on the line 2-2 of Fig. 1.

In the drawings, the spark plug is shown as comprising an outer jacket or casing 3 having an hexagonal or other flat sided portion 4 for turning the same into the pening in the engine provided for screwthreadedly receiving the screw threads 5 on said casing or outer shell 3. WVithin said casing or outer shell 3 is provided an insulator 6 made of any desired insulating material, which is held in place in the plug by means 6, 1922. Serial No. 599,390.

of the nut 7. Within said insulating material is provided the firing pin 8 which er;- tends upwardly beyond the end of the insulator providing the screwthreaded end portion 9 which has the nut 10 and the binding screw 11 provided thereon for securing the electrical conductor for supplying the current to the spark plug thereto. The insulating material around the central electrode or firing pin 8, it will be seen, closely engages the inner bore of the casing or shell 3,

except at the lower end thereoi where the same is cut away so as to provide a reduced end portion 12 surrounding the firing pin or central electrode 8, said electrode extending beyond the end thereof, as clearly shown in F ig. 1. The insulating material 12 is provided with a rounded corner at 13, and the outer end portion thereof may be rounded as shown at 1 1. The end of the casing or shell 3 is provided with an annular flange 15 which has an opening 16 therein sur-. rounding the pin 8, said flange 15 being provided with an upturned portion 17 which has a concave face portion 18 so as to provide an annular runway or ball race on the inner face of said flange 15; Seated within the casing 3 and between the flange 15 and the insulating material 12., is the ball or sphere 19 which is adapted to rest as shown in Fig. 1 in electrical contact with the casing 3 or the flange 15.

It will be noted that the ball 19 is confined between the inner face 21 of the side wall portion of the casing between the flange 15 and the corner 14 of the insulator. T he spacing of the parts is such that the ball 19 will be prevented from moving nearer to the pin 8 in one position than in the other. and that the same will be more closely spaced relative to the pin 8 than any other portion of thedevice. Thus the spark will jump from the ball to the pin or vice versa. and as the flange 15 is downward when the plug is in posi ion, the action ofgravity will be to hold the ball 19, except when thrown temporarily upwardly against the corner 1 1 due to some shock, in engagement with the flange 15. As the flange 15 is made in the form of an annular ball race on the inner face thereof, the ball 19 when in contacting position therewith, will be held at a prede termined spaced distance from the central contact or firing pin 8, but will be free to move around in said ball race dependent upon the inclination of the vehicle, and upon llll III

the shocks to which the spark plug is subjected, and is also free to have a slight upward play due to shock, said parts being spaced sufiiciently. to allow fora sufficient play of along the guideway for the same.

the ball 19so that the same 'willea-sily travel It will be seen that due to the movements a movably mounted electrode and means for constraining said inovably moimtedelectrode to move in a fixed path around said stationary electrode. i

2. In a spark plug. a'statiouary electrode, airelectrode adapted to roll in said spark plug, and means for guiding the rolling movement thereof to maintain a substantially constantgap. between said electrodes.

3. A'spark plug comprising casing. a

stationary electrode therein, a movably mounted member engaging said casing and serving as the other electrode for said plug, and means for guiding the movements of said member around said stationary electrode in a fixed path.

e. A spark plug comprising a casing, a stationary electrode therein, a guideWay concentric with said electrode within said casing and a hall electrode adapted to move in said guideway.

A spark plug comprising a casing, a stationary electrode therein, a ball race concentric with said electrode within said casing and a ball electrode adapted to move in said ball race. 7

b. A self cleaning spark plug comprising a casing, a stationary electrode therein and a loosely mounted electrode therein adapted i'ihBRIEL J. JACOMINI. 

